I'm not much of a modern country music fan and don't really have anything for or against the Dixie Chicks, but why must it be they who are in the role of martyrs? They're pretty ladies, basically, and quite talented musicians (check out their performance on Austin City Limits of a few years ago), but they don't strike me as particularly exalted heroines in the question of who has a right to say what and where and when it should be said. They're no better in this role than Luther Campbell or Larry Flynt.
No, Natalie Maines isn't a traitor for telling a British concert audience that she and her bandmates are ashamed that the President hails from their own home state, but she's quite possibly a dumbass for doing so. Country music fans are a pretty conservative bunch and it is a huge commercial blunder to put them in the position of having to defend their President against the opinions of a favorite music group. (Then again, I love John Lennon and his music dearly, but have never felt threatened by his politics.) Ultimately, it was a gratuitous thing to say and she certainly didn't need to curry favor with a paying audience. If she had wanted to be on record as being opposed to the war, she could have said the same thing she did say to a magazine reporter and would at least have spoken her mind in a less turbulent setting.
Anyhow, the point is this: Maines is entitled to her opinion. That's the American Way. She should never be threatened with death or personal harm of any kind for what she said. That is not the American Way. But in the absence of killing or harming her (something the Baathists or Stalinists would have had no problem doing), there is, in fact, a very American way of responding to her with a passion equal to hers: protest and boycott. How do you take down a well-paid commercial artist? You cut her off and withdraw your support. That's not execution for treason; that's discretion after indiscretion.